Barrier-Free French Door Forend Cap Sealing

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Solution Overview

Problem

Barrier-free French doors experience sealing issues with driving rain, as water is pressed into the area below the forend profile and can penetrate into the threshold and gap between the door leaves.

Innovation Solution

A soft plastic forend cap is designed to seal against driving rain, covering the gap between the threshold profile and weatherboards, with flexible adaptations for thermal expansions, and features U-shaped grooves for brush seals and backwater-repellent leg elements to ensure drainage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a flat threshold profile is used in barrier-free French doors, then accessibility is improved, but sealing performance deteriorates due to driving rain penetration

Engineering Contradiction:
ImproveaccessibilityVSAvoidsealing performance
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The sealing system is divided into multiple components: the forend profile for basic closure, the forend cap made of soft plastic for sealing the gap between threshold and weatherboards, and brush seals in U-shaped grooves for additional protection. This segmentation allows each component to address specific sealing requirements while maintaining the flat threshold for accessibility.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The forend cap made of soft plastic acts as an intermediary element between the rigid forend profile and the threshold/weatherboards. This soft plastic component flexes to maintain contact and sealing pressure, effectively bridging the gap created by the flat threshold design while preventing driving rain penetration.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If the forend profile is made rigid to ensure structural stability, then structural stability is improved, but adaptability to thermal expansion deteriorates

Engineering Contradiction:
Improvestructural stabilityVSAvoidadaptability to thermal expansion
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The forend cap is made of soft plastic, a flexible material that can deform and adapt to thermal expansions and contractions of the underlying structure. This flexible outer layer maintains sealing contact while allowing the rigid forend profile to remain structurally stable.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The sealing system transitions from a static rigid structure to a dynamic system where the soft plastic forend cap can move and deform in response to thermal changes. This dynamic adaptation ensures continuous sealing performance despite dimensional changes in the door structure.

Inventive Principle:
Principle #15Dynamics

3Object-affected harmful factors

If the gap between door leaves is reduced to improve sealing, then sealing performance is improved, but the functional requirement for variable passage opening deteriorates

Engineering Contradiction:
Improvesealing performanceVSAvoidvariable passage opening
Core Design Contradiction:
Object-affected harmful factorsVSAdaptability or versatility

Solution Approach 1:

The sealing components (forend cap and brush seals) are concentrated at the critical lower gap area between the door leaves and threshold. This localized sealing approach maintains effective weather protection while leaving the upper portions of the door leaves free to provide variable passage openings as required.

Inventive Principle:
Principle #3Local quality

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution effectively prevents rainwater from penetrating into the door frame, maintaining tightness and ensuring the area below the forend profile is protected from driving rain, with flexible adaptations and drainage features.

Implementation Method 1

The design of the cuff cap made of soft plastic advantageously adapts flexibly to thermal expansions that occur in the area of the lower transverse beam profiles of the fixed leaf and active leaf, so that the required tightness is maintained.

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

In the rear area of the cuff cap, U-shaped grooves are formed to accommodate brush seals, so that this area in particular is also covered by brush seals, which extend below the transverse beams of the rotating vanes.

Methodology Applied
Scientific EffectMechanical sealing:

Implementation Method 3

In a further development of the invention, backwater-repellent leg elements are formed in the hollow chamber extending between the rear and the front area of the cuff cap. These should ensure that the water that has entered the construction of the gauntlet cap due to the wind pressure is safely drained away again.

Methodology Applied
Scientific EffectGravity-driven drainage: Gravitation

Data Source

PatentEP2290187B1Door in the form of a barrier-free French door
Publication Date: 2014.02.26 GRUNDMEIER
  • EP2290187B1 patent drawingFigure 1
  • EP2290187B1 patent drawingFigure 2
  • EP2290187B1 patent drawingFigure 3

AI summary

The door has a frame which is inserted in a brickwork opening with a flat door sill profile (3) which is kept in threshold area. Two revolving door leaves are arranged in the frame. A shield end cap (10) formed from soft plastic is arranged in a lower free end of a shield profile (7). The shield profile is formed such that it tightly covers a gap (11) for door sill profile on one hand. A clearance (12) is tightly covered between the weatherboard profiles (13,14) fastened at the upper frame profiles (8,9).